The invention relates to hinges, especially piano type hinges which are spring loaded and used in lightweight applications, such as on small lightweight metal, plastic or wood doors. Such hinges are usually made of plastic, but can be made of light gage metal, such as aluminum, steel or brass.
It is known to use a highly visible, exteriorly mounted coil spring between the two leafs of a piano hinge to spring load the hinge. Moreover, U.S. Pat. No. 4,823432 discloses a piano hinge with a split hinge pin that employs a concealed, flat piece of spring metal, between adjacent ends of the split hinge pin, to spring load the piano hinge.
The invention is designed to produce a lightweight hinge which is economical to manufacture and repair.